Protective headgears are used for both outdoor and indoor activities, e.g. cycling. When riding, the cyclist is prone to fall from--or be thrown off--his bicycle and his head may hit a hard surface with relatively high velocity. The injuries resulting from such an impact may lead to dire consequences such as permanent damage to the skull, the spine, or even the death of the cyclist. This is the reason why protective helmets have a growing popularity among cyclists.
One type of protective headgear for a cyclist is described in the U.S. Pat. No. 5,351,342, issued in 1994 to the applicant Louis Garneau. This helmet comprises an inner soft shock-absorbing insert and an outer more rigid shell embedded on the periphery of the former. A plurality of ventilation openings are fitted in registration through both layers. The helmet is provided with a retention strap, of known construction at the time the patent was issued, that is inserted into predetermined transverse openings of the helmet. Two rear openings communicate with one another by means of a transverse groove positioned at the rear part of the helmet between the external shell and the insert. Similarly, two front openings communicate by means of another transverse groove positioned at the front part of the helmet between the insert and the external shell. As shown in FIGS. 3a and 4a of the patent, the strap overlies the above-mentioned grooves and passes through both the above-mentioned rear and front openings to extend well under the insert. In use, the front straps are destined to lie alongside the temples and the cheeks, while the rear straps are destined to lie alongside the skull behind the ears, each front strap joining one rear strap just under the ear. Each pair of front and rear straps can then be removably secured with strap fasteners of known construction.
Such a helmet covers the upper hemisphere of the head and is to be strapped under the chin of the wearer for fastening it to the head. These helmets often protect adequately the head of the cyclist, but are prone to tilt forward during the chaos of the fall and the resulting impacts. Indeed, the straps are laterally positioned, relative to the cyclist's head, and therefore reduce or prevent the lateral tilting of the helmet. Also, the downwardly extending rear end of the helmet combined with the front part of the fastening strap prevent most of the backward tilting. However, frontward tilting of the helmet in the sagittal plane is a more probable and therefore dangerous occurrence, since the front end of the helmet does not extend downwardly very far to prevent the obstruction of the visual field of the wearer. The helmet may consequently tilt significantly when impacting with a hard surface. This is of course highly undesirable, since a second impact after the helmet has thus moved could occur on important and uncovered parts of the head.
To obviate this important disadvantage, some helmets were designed with a rigid abutment plate downwardly depending from the rear end of the helmet through the instrumentality of an integral rigid elongated link pivotally attached to the helmet. The link and abutment plate, by means of the pivotable attachment of the former, can pivot back and forth at the rear of the helmet, the abutment plate being positioned just under the helmet insert and two rearwardly oriented extremities of the fastening strap being attached to it. Thus, when the fastening strap is fastened under the chin of the cyclist, the rearwardly oriented extremities pull on the abutment plate to pivot the latter towards the head of the cyclist until it abuts on said head, on the occipital bone. The helmet is thus less likely to tilt frontwardly, for the abutment plate will retain it in that direction.